Overhead cam conversion kit



Oct. 14, 1969 1', c. CHAMBERLAIN 3,

OVERHEAD CAM CONVERSION KIT :5 Sheets-Sheet 1 Filed June 21. 1967 IN VENTOR.

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ATTORNEY ,1969 'r. c. CHAMBERLAIN 3, 72,212

OVERHEAD CAM CONVERSION KIT 3 Sheets-Sheet 2 Filed June 21, 1967 INVENTOR. C W

0d. 14, 1959 1'. c. CHAMBERLAIN 3, 72, 12

OVERHEAD CAM CONVERSION KIT Filed June 21, 1967 3 Sheets-Sheet 3 INVENTOR BYQQW ATTORNEY 3,472,212 OVERHEAD CAM CUNVERSHON KIT Ted 6:. (Iharnberlain, PA). Box 722, Lakewood, NJ. 03701 Filed June 21, I967, Ser. No. 647,678 Int. Cl. Ftill 1/00; FOZf 7/00 US. Cl. 123-90 Claims ABSTRACT OF THE DHSCLGSURE A kit for converting an internal combustion engine having rocker arm valve actuators into an engine having overhead cam valve actuators. The kit includes the necessary component parts for effecting such a conversion and comprises a boss plate having openings for receiving the cam followers, supports having bearings for receiving a cam shaft, a plurality of cam follows, a cam shaft, a cam shaft extension and its supporting structure, seals, bearings and oil slingers for the extension, timing pulleys having removable flanges, belts for the pulleys, and a cover for the component parts after the conversion is completed.

Background of the invention While the prior art is aware of overhead cams utilized in association with internal combustion engines, there has been no progress in the art for converting an engine having the conventional rocker arm valve actuators to one having an overhead cam for operating the valves. As is well known to automotive engineers, hot rodders, and sports car enthusiasts, there are many benefits and advantages accruing to the location of a cam adjacent the valve. Some of these advantages are (1) the lifters and push rods for actuating the valves can be discarded to thereby eliminate a great deal of the weight, (2) removal of these parts therefore solves the problems caused by the reciprocal weight thereof, e.g., the balancing of the same, (3) faster and simpler valve action, (4) approximately a 40% smoother running engine, especially at high speeds, (5) a more efficient engine, (6) absolute minimum valve guide wear due to the lack of side thrust by the rocker arm, and (7) from an economical standpoint, since there are fewer parts, the initial cost and the repair cost of the component parts will be greatly reduced due to the location and accessibility of the cams.

Summary of the invention In view of the known advantages, a kit has been provided which will permit any person, whether skilled or unskilled, to convert a conventional engine utilizing a rocker arm valve actuator into one having an overhead cam valve actuation.

Briefly, in utilizing the kit during the conversion process, the push rods and rocker arms associated with the original cam shaft and valves are removed and discarded. A boss plate is then secured to the cylinder head on rocker shaft pillow supports positioned thereon. The boss plate is provided with a plurality of machined openings coinciding with the location of the valves. These openings receive the cam followers, each of which are positioned 3,472,212 Patented Oct. 14, 1969 directly over the valves. If hydraulic lifters were utilized in the original engine, the followers are provided with passages in order to provide continual passage for the oil. The cam shaft is then placed in supports directly over the aforementioned cam followers. Due to the fact that a conventional cam shaft is furnished with the kit, it is necessary to provide an extension therefor in order that the same may receive the new and novel timing pulleys featuring removable flanges, which permit the use of a precision belt without using an idler pulley.

Brief description of the drawings FIGURE 1 is a side view of a stock slant 6-cylinder engine head showing several of the component parts of the kit when assembled;

FIGURE 2 is a side elevational view of the modified pulley furnished with the conversion kit;

FIGURE 3 is an end view showing the cam and follower as assembled when viewed from the right of FIG- URE 1;

FIGURE 4 is a side elevational view showing the details of the cam and one of the followers as shown in FIGURE 3;

FIGURE 5 is a sectional view taken on line 55 of FIGURE 1;

FIGURE 6 is a sectional view taken on line 6-6 of FIGURE 5.

Description of the preferred embodiment By the way of background to the invention and to provide a clear understanding thereof, it is pointed out that generally and regardless of what type of engine is to be converted, whether it be a 4-cylinder, 6-cylinder or 8- cylinder, the original valve lifters must be removed and discarded along with the push rods, rocker arms, rocker arm shaft, and the rocker arm spacers, if any. In other words, the complete rocker arm assembly is discarded. The original valve cover is discarded and is ultimately replaced by a suitable cam cover. During the conversion the original cam shaft may remain in the block of the engine only to drive the fuel pump, oil pump, and distributor. However, it may be removed if it is desired; in which case the fuel pump, oil pump, and distributor may be driven from the new overhead cam to be placed at the top of the engine.

Now referring to the drawing and particularly to FIG- URE 1, the numeral 10 designates a conventional stock slant 6-cylinder engine wherein the rocker arm assembly for valve actuation has been removed and discarded. The elongated boss plate 11 which extends to substantially the length of the head 10 has been secured thereto in a manner to be explained hereinafter. The plate 11 is provided with a plurality of spaced openings 12 arranged over the major portion thereof to axially coincide with the poppet inlet and outer valves 13, as depicted in FIGURE 4. Each of these openings receive a cam follower 14 which takes the form of a cylinder having flat ends 15. While the followers 14 may be manufactured either in solid form or as a shell having a hollow interior, they must be snug fit in their respective openings 12 in a manner to provide a clearance for the passage of oil.

With reference to FIGURE 3, the cylinder head 10 is shown in its slanted position with an upwardly extending pillar support 16. These supports 16 originally supported the rocker arm shaft which was discarded in the conversion process and a plurality of them are spaced along the cylinder head in known fashion. Supported on the members 16 is the boss plate 11 which is generally flat, elongated and rectangular in configuration and is provided with a protuberance 17 which is adapted to be seated at 18 within the member 16. The plate 11 is also formed with spaced bifurcated legs 19 adapted to straddle the head bolts 20 in a manner as shown in FIGURE 1.

Disposed upwardly from the plate 11 is a generally triangular shaped member 21 which may, if desired, be formed integrally with the boss plate 11, or may be removably connected thereto. The triangular shaped members 21 are disposed at different intervals along the distance of the plate 11 and are formed with a circular recess 22 which receives a conforming bearing housing 23 therein. These housings 23 are formed integral with the cam shaft 24. The triangular shaped members together with the spaced housings 23 support the shaft at different intervals therealong, and as seen in FIGURE 1, four such supports are furnished. The number of supports 21 required for supporting the cam shaft will be dictated by the number of bearing journals provided on the shaft. The shaft is provided with a plurality of lobes 25, each of which are positioned directly over the followers 14 for ultimately controlling the valves.

As was mentioned hereinabove, the cam shaft support members 21 can be formed separately from the plate, and when so provided, they are secured to the plate 11 by bolts or other removable fasteners 27, as is seen in FIGURE 1. It may be necessary to utilize shims beneath the cam supports 21 in order to dispose the same on the plate 11 in a manner to insure the correct alignment of the cam shaft.

After the cam shaft with its spaced bearings are assembled in the cut-out portion 22 of the supports 21, a generally inverted U-shaped cover member 28 is disposed over the bearings 23 and is bolted at one end to the supports 21 by a bolt 29 and is secured at its other end to the pillar support 16 by a bolt 30. The bolt 30 extends through the plate 28, boss plate 11 and into the pillar support 16 to thereby secure the boss plate 11 with its openings 12 in alignment with the valves. Additionally, and as is noted from FIGURE 3, the cover member 28 is so shaped that its falls within the confines of two spaced vertical planes extending upwardly from the ends of the cylinder head in order to provide a compact unit. After the plate 11 is in position, the cam followers 14 are inserted in the openings 12 with one side thereof engaging the poppet valve stem 18' of the valve 13 having the biasing spring 19' urging the stem upwardly into engagement with the follower 14. The spring 19" is disposed between the cylinder head 11 and a retaining cap secured to the stem 13'.

As is clearly seen from FIGURES 3 and 4, the followers 14 are positioned directly beneath the lobe and above the valve stem, in order that a straight unobstructed valve action can be obtained without any side thrust forces action on either the follower or valve. The shims mentioned above with reference to the triangular supports 21 serve to insure the attaining of proper clearance between the cam and the cam follower.

With continuing reference to FIGURE 1, a housing 31 is provided at the left end of the modified engine within which is positioned a cam shaft extension. The necessity of the cam shaft extension is brought about by the fact that the kit is provided with a standard stock cam shaft having an insufficient length to support the timing belts in a clear, clean manner away from the cylinder block and in line with the bottom crank shaft pulley. The extension overcomes this deficiency by adding extra length to the shaft. It should be noted, however, that the extension can be done away with if a cam shaft of sufiicient length were to be provided in the kit. Due to the cost 4 factor and availability of stock cam shafts the same are furnished with the kit.

FIGURE 5 depicts the detail and the manner of connecting the cam shaft extension 411 to the newly installed cam shaft 24. The shaft extension 411 which is of the same general circumference as that of the cam shaft is provided with an axially threaded bore 42 which is in alignment with a threaded bore 43 provided in the cam shaft 24. An Allen-type screw 43' is slipped through the bores 42, 43 and couples the extension 40 to the shaft 24. It is to be noted that the extension at is provided with at least one dowel pin 44 to facilitate its connection to the shaft 24. After abutting the end of the extension to that of the cam shaft 24, a needle bearing assembly 44 is slipped around the abutted ends in order to complete the alignment therebetweeen. Remote from the abutting ends and on turned down portion 48, an oil slinger 46 (shown schematically) is provided and cooperates with an installed oil seal 47 to remove excess oil therefrom. Adjacent turned down portion 48 is turned down portion 49 whereat threads 50 are provided for a reason to be explained hereinafter. Adjacent the turned down portion 48, a press fit annular sealed ball bearing assembly 51 is provided and receives U-shaped strap member 5'2 therearound which is adapted to be secured by bolts 53 to provide a thrust bearing and load supporting structure for the cam shaft extension. The turned portion 49 receives the timing pulley 54 which is provided with an opening 55. A nut 56 locks the pulley to the extension by threading the same to the threads 51).

The novel timing pulley 54 as designed for this kit, see FIGURE 2, comprises a circular housing 60 having timing belt teeth 60' extending about its circumferential surface and outwardly extending flanges 61, 61, one of which is removably secured to the housing 60 by the use of screws 62 extending through the flange and into the housing. Alignment of the removable flange with the housing is facilitated by the provision of a stepped portion 63 formed on the housing 60. Referring to FIGURE 1, it will be seen that within the housing 60 a main body 65 taking the configuration of a spider is provided for reinforcing the same, and which is provided with an opening aligned with the aforementioned opening 55.

The advantages of the removable flange are apparent in that the belt can be easily removed and replaced, and foremost, the use of an idler pulley in the drive can be avoided to thereby prevent any excessive stretching of the belt which can cause movement of the cam shaft as well as effecting the timing of the engine.

Additionally, and as seen in FIGURE 6, a plurality of aligning pins are shown circumferentially spaced adjacent the turned down portion 49 for facilitating the alignment and connection of the pulley to the cam shaft extension.

I claim:

1. A kit fo converting an internal combustion engine having rocker arm means for actuating the valves to one having an overhead cam actuating means comprising plate means including openings designed to be aligned with the valves of an engine, support means for supporting the first-mentioned means in said aligned position, actuating means comprised of individual closed end members having a body of substantially constant cross section positioned in each of said openings in snug but moveable relationship therewith with one of said ends engaging and controlling actuation of said valves, a cam shaft positioned above said actuation means including cams for each of said members and engaging said other ends thereof for controlling the same, said cam shaft being of sufficient length to support said pulley, said length being comprised of an extension having means connecting the same to said cam shaft and further including support means providing a thrust bearing and load support for said extension, and means including a pulley secured to said shaft co-operating with said shaft for driving the same.

2. The kit of claim 1 wherein the pulley is formed of a main body having flanges thereon, wherein at least one thereof includes means to removably secure it to said body.

3. The kit of claim 1 wherein the means for supporting the plate is comprised of supports spaced over the length of the engine head which are adapted to cooperate with the supports of the rocker arm shaft which was removed.

4. The kit of claim 3 wherein an oil slinger and oil seal are positioned on the shaft extension for controlling the oil within the support housing.

5. The kit of claim 4 wherein a cover is provided for enclosing the actuating means, cam shaft and supports therefor.

References Cited UNITED STATES PATENTS Belford 123-52 Haroldson 74-2303 Bouvy.

Dadd Dolza.

Hulten 123-193 X Trapp.

Smith.

Burks.

AL LAWRENCE SMITH, Primary Examiner US. Cl. X.R. 

